GENEVA

Researchers at the University of Geneva have identified an unexpected role of the cerebellum in the development of schizophrenia's most disabling symptoms, uncovering a link that could pave the way for new non-invasive treatments.

In a study published on Tuesday, a team from the university and Geneva University Hospitals described for the first time the interaction between the cerebellum and the brain’s reward system in people with schizophrenia.

Schizophrenia affects around 1% of the population and is widely associated with hallucinations and delusions, but researchers say its so-called “negative” symptoms, including apathy, loss of motivation, and social withdrawal, are often more disabling and lack effective treatments, it said.

"We show that stronger cerebellar regulation of the reward system is associated with a reduction in negative symptoms — and conversely, weaker regulation with an increase in symptoms," Jade Awada, first author of the study, said. "This newly identified mechanism opens up promising avenues for targeted therapeutic interventions."

The research focused on the ventral tegmental area (VTA), a dopamine-producing region linked to motivation and reward processing, which is believed to be overactive in people with schizophrenia.

By following 146 patients over three to nine months and analyzing an independent cohort,
researchers identified a functional connection between the cerebellum and the VTA, according to the statement.

"What is sometimes called our 'little brain' actually contains 50% of all our neurons," said Indrit Begue, who led the study. "Although it was long considered to have a purely motor function, we are now discovering that it also plays important emotional and cognitive roles."

Unlike the VTA, the cerebellum is "far more" accessible, making it a potential target for non-invasive therapies such as transcranial magnetic stimulation.

A randomized controlled trial is already under way, with results expected in 2028, the statement added.